U.S. patent application number 16/126861 was filed with the patent office on 2020-03-12 for valve assembly and method of cooling.
The applicant listed for this patent is Aventics Corporation. Invention is credited to Oswaldo Baasch, Jon A. Bigley, Danny W. Brown, Glenn Wethington.
Application Number | 20200080662 16/126861 |
Document ID | / |
Family ID | 69720646 |
Filed Date | 2020-03-12 |
View All Diagrams
United States Patent
Application |
20200080662 |
Kind Code |
A1 |
Baasch; Oswaldo ; et
al. |
March 12, 2020 |
VALVE ASSEMBLY AND METHOD OF COOLING
Abstract
This present invention relates to a fluid flow control device,
such as a valve in an internal combustion exhaust pipe. The fluid
flow control device includes a valve assembly and an actuator
assembly. The fluid flow control device further includes a cooling
ring positioned between the actuator assembly and valve assembly in
order to thermally isolate the sensors, controllers and other
elements of the actuator assembly from heat that may be present in
the valve assembly.
Inventors: |
Baasch; Oswaldo; (Bowling
Green, KY) ; Bigley; Jon A.; (Bowling Green, KY)
; Brown; Danny W.; (Bowling Green, KY) ;
Wethington; Glenn; (Oakland, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aventics Corporation |
Lexington |
KY |
US |
|
|
Family ID: |
69720646 |
Appl. No.: |
16/126861 |
Filed: |
September 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K 1/221 20130101;
F15B 2211/7058 20130101; F16K 31/1635 20130101; F15B 15/12
20130101; F01P 1/08 20130101; F02M 26/70 20160201; F16K 27/0218
20130101; F16K 49/005 20130101; F15B 15/1485 20130101; F02M 26/73
20160201; F01P 2060/16 20130101; F02M 26/59 20160201 |
International
Class: |
F16K 31/163 20060101
F16K031/163; F16K 27/02 20060101 F16K027/02; F16K 1/22 20060101
F16K001/22; F16K 49/00 20060101 F16K049/00; F01P 1/08 20060101
F01P001/08; F02M 26/59 20060101 F02M026/59; F02M 26/70 20060101
F02M026/70 |
Claims
1. A fluid flow control device, comprising: a valve assembly
comprising: a valve housing, and a movable valve element; an
actuator assembly comprising: an actuator housing, and a movable
actuator element; a shaft connecting the movable actuator element
with the movable valve element; and a first cooling ring positioned
between a surface of the valve housing and a surface of the
actuator housing, the cooling ring comprising: a first surface
facing toward the valve assembly, a second surface facing toward
the actuator assembly, a cooling channel, and a cooling inlet port
that extends through the first surface.
2. The fluid flow control device of claim 1 wherein the first
cooling ring has a thickness extending between the first surface
and the second surface and a diameter that is greater than the
thickness.
3. The fluid flow control device of claim 1 wherein the first
cooling ring further comprises an outlet port that extends through
the first surface.
4. The fluid flow control device of claim 1 wherein the first
cooling ring further comprises an outlet port that extends through
the second surface.
5. The fluid flow control device of claim 4 further comprising a
second cooling ring positioned adjacent to the first cooling ring,
the second cooling ring comprising a first surface facing toward
the valve assembly and a second surface facing toward the actuator
assembly.
6. The fluid flow control device of claim 5 wherein the second
cooling ring comprises an inlet port that extends through the first
surface and an outlet port that extends through the second
surface.
7. The fluid flow control device of claim 6 wherein the outlet port
of the first cooling ring is aligned with the inlet port of the
second cooling ring.
8. The fluid flow control device of claim 1 wherein a center plane
of the cooling channel is positioned midway between the first and
second cooling ring surfaces.
9. The fluid flow control device of claim 1 wherein a center plane
of the cooling channel is positioned closer to the first cooling
ring surface than the second cooling ring surface.
10. The fluid flow control device of claim 9 wherein the second
cooling ring surface comprises a recess.
11. The fluid flow control device of claim 1 wherein the valve
housing comprises a fluid passage that extends through a portion of
the actuator housing and is fluidly connected with the first
cooling ring inlet port.
12. The fluid flow control device of claim 3 wherein the valve
housing comprises a fluid passage that extends through a portion of
the actuator housing and is fluidly connected with the first
cooling ring outlet port.
13. The fluid flow control device of claim 4 wherein the actuator
housing comprises a fluid passage that extends through a portion of
the actuator housing and is fluidly connected with the first
cooling ring outlet port.
14. A fluid flow control device, comprising: a valve assembly
comprising: a valve housing, and a movable valve element; an
actuator assembly comprising: an actuator housing, and a movable
actuator element; a shaft connecting the movable actuator element
with the movable valve element; and a cooling ring positioned
between a surface of the valve housing and a surface of the
actuator housing, the cooling ring comprising: a first surface
adjacent to the valve assembly, a second surface adjacent to the
actuator assembly, a cooling channel containing cooling fluid, and
a cooling inlet port that extends through the second surface.
15. The fluid flow control device of claim 14 wherein the actuator
housing comprises a first fluid passage that extends through a
portion of the actuator housing and is fluidly connected with the
cooling ring inlet port.
16. The fluid flow control device of claim 15 wherein the cooling
ring further comprises an outlet port that extends through the
cooling ring second surface.
17. The fluid flow control device of claim 16 wherein the actuator
housing further comprises a second fluid passage that extends
through a portion of the actuator housing and is fluidly connected
with the first cooling ring outlet port.
18. The fluid flow control device of claim 15 wherein the cooling
ring further comprises an outlet port that extends through the
cooling ring first surface.
19. The fluid flow control device of claim 18 wherein the valve
housing further comprises a fluid passage that extends through a
portion of the valve housing and is fluidly connected with the
first cooling ring outlet port.
20. A fluid flow control device, comprising: a valve assembly
comprising: a valve housing, a valve housing fluid passage
extending through a portion of the valve housing, and a movable
valve element; an actuator assembly comprising: an actuator
housing, an actuator housing fluid passage extending through a
portion of the actuator housing, and a movable actuator element; a
shaft connecting the movable actuator element with the movable
valve element; and a first cooling ring positioned between a
surface of the valve housing and a surface of the actuator housing,
the cooling ring comprising: a first surface facing toward the
valve assembly, a second surface facing toward the actuator
assembly, a cooling channel containing cooling fluid, a first
cooling port that extends through the first surface and is fluidly
connected with the valve housing fluid passage, and a second
cooling port that extends through the second surface and is fluidly
connected with the actuator housing fluid passage.
Description
RELATED APPLICATION
[0001] This application claims priority as a continuation of U.S.
patent application Ser. No. 15/057,636, filed Mar. 1, 2016 and
entitled "Valve Assembly and Method of Cooling," which application
claims priority to U.S. Provisional Application No. 62/127,164,
filed Mar. 2, 2015 and also claims priority as a continuation in
part of U.S. patent application Ser. No. 14/471,410 filed Aug. 28,
2014, entitled "Remote Electro-Hydraulic Actuator," which
application further claims priority to U.S. Provisional Application
No. 61/871,564 filed Aug. 29, 2013. Each of these applications is
incorporated by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to a valve assembly. In
particular, embodiments of the invention relate to a valve assembly
having a coolant ring to provide thermal isolation to an actuator
assembly. Further embodiments of the invention relate to a valve
assembly with an improved mechanism for attaching a valve
plate.
BACKGROUND
[0003] Industrial, residential and mobile, including power
generation, transportation, automotive and aerospace, controls
systems often require actuation of mechanical components.
Mechanical components of such systems may include valves that must
be actuated. Such actuation is generally accomplished via
pneumatic, hydraulic or electric components and/or systems. There
are generally three different remote controlled types of valve
actuation.
[0004] Valve actuation may be accomplished by electric components,
including permanent magnet direct current (PMDC) motors, brushless
direct current (BLDC) motors, direct current stepper motors, linear
or rotary solenoids. Electric actuation is susceptible to
environmental temperatures and suffers from reliability issues,
especially in mobile applications due to the variations in
operating environment and the harsh engine compartment/under hood
environment.
[0005] Valve actuation may also be accomplished by pneumatic or
electro-pneumatic means using pneumatically controlled linear or
rotary actuators. Such actuators may include on/off or proportional
actuation. Pneumatic and electro-pneumatic systems suffer from low
position accuracy due the compressible nature of the fluid,
typically atmospheric air, used for actuation and the moisture
generated in the air compressor system.
[0006] In addition, valves in mechanical systems may be actuated by
electro-hydraulic means, using hydraulically controlled linear or
rotary actuators. Such actuators may employ on/off or proportional
control. Conventional electro-hydraulic actuators use oil from the
engine lubricating system or other high-pressure hydraulic power
assist systems. The pressures of the engine lubricating systems are
in the neighborhood of 100 psi and vary with engine speed.
BRIEF DESCRIPTION OF THE PRIOR ART
[0007] Electro-hydraulic actuators are known in the prior art. For
example, U.S. Pat. No. 7,419,134 to Gruel is titled "Valve
Actuation Assembly." European Patent Publication No. EP 0 248 986
to Vick et al. is titled "Rotary Vane Hydraulic Actuator." U.S.
Pat. No. 5,007,330 to Scobie et al. is titled "Rotary Actuator and
Seal Assembly for Use Therein. U.S. Pat. No. 6,422,216 to Lyko et
al. is titled "Exhaust Gas Recirculation Valve."
[0008] Electro-mechanical actuators are also known in the prior
art. For example, U.S. Pat. Nos. 7,591,245 and 7,658,177 to Baasch
at al. are titled "Air Valve and Method of Use." Int'l Pub.
Application No. WO 2010/123889 to Baasch is titled "Exhaust Gas
Recirculation Valve and Method of Cooling."
APPLICATION OF THE INVENTION
[0009] Embodiments of the invention may be used, for example in
automotive, aeronautical, rail or other transportation applications
of internal combustion engines. In order to minimize pollutants
produced by internal combustion engines, a portion of the engine
exhaust may be recirculated to an intake of the engine. An exhaust
gas recirculation (EGR) valve, such as a mixing valve, may be used
to assist in directing the portion of the exhaust to the intake.
Such valves typically require a great deal of torque for actuation
during engine operation. In addition, such valves are often
disposed within the engine compartment and, thus, require compact
actuation assemblies due to space constraints.
[0010] This application incorporates by reference U.S. Provisional
Application No. 61/871,564 filed Aug. 29, 2013, U.S. patent
application Ser. No. 14/471,410 filed Aug. 28, 2014, and
International App. No. PCT/US2014/053108 filed Aug. 28, 2014, all
entitled "Remote Electro-Hydraulic Actuator."
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a perspective view of a single vane rotary
actuator as is known in the prior art.
[0012] FIG. 2 shows a perspective view of a piston rotary actuator
as is known in the prior art.
[0013] FIG. 3 shows a cross-sectional view of the piston rotary
actuator of FIG. 2.
[0014] FIG. 4 shows a perspective view of a valve and actuator in
accordance with embodiments of the present invention.
[0015] FIG. 5 shows a top view of the valve and actuator of the
embodiment of FIG. 4.
[0016] FIG. 6 shows an exploded view of a valve assembly according
to an embodiment of the invention.
[0017] FIG. 7 shows and exploded view of an actuator assembly
according to an embodiment of the invention.
[0018] FIG. 8 is a perspective view of the actuator assembly of
FIG. 7.
[0019] FIG. 9 is a perspective view of an actuator main housing
according to an embodiment of the invention.
[0020] FIG. 10 shows a top view of a vane rotational assembly
according to an embodiment of the invention.
[0021] FIG. 11 shows a perspective view of the vane rotational
assembly of FIG. 10.
[0022] FIG. 12 is a partial cross-sectional view of an actuator
assembly in accordance with an embodiment of the invention.
[0023] FIG. 13 is a cross-sectional view perpendicular to the
rotational axis of an upper actuator assembly cover in accordance
with an embodiment of the invention.
[0024] FIG. 14 is a cross-sectional view parallel to the rotational
axis of an upper actuator assembly cover in accordance with an
embodiment of the invention.
[0025] FIG. 15 is a second cross sectional view of the upper
actuator assembly cover of FIG. 14.
[0026] FIG. 16 is a perspective view of a lower actuator assembly
cover in accordance with an embodiment of the invention.
[0027] FIG. 17 is a perspective view of an upper actuator assembly
cover in accordance with an embodiment of the invention.
[0028] FIG. 18 is a perspective view of a spool valve as used in
embodiments of the invention.
[0029] FIG. 19 is a perspective view of the upper actuator assembly
cover of FIG. 17.
[0030] FIG. 20 is a perspective view of a valve and actuator in
accordance with embodiments of the present invention.
[0031] FIG. 21 is a cross-sectional view of the valve and actuator
of FIG. 20.
[0032] FIG. 22 is a perspective view of a valve assembly in
accordance with embodiments of the present invention.
[0033] FIG. 23 is an exploded view of the valve assembly of FIG.
22.
[0034] FIG. 24 is a cross-sectional view of the valve assembly of
FIG. 22.
[0035] FIG. 25 is a cross-sectional view of an embodiment of a
shaft and pin for use with the valve assembly of FIG. 22.
[0036] FIG. 26 is a cross-sectional, perspective view of an
embodiment of a valve body and coolant bushing for use with the
valve assembly of FIG. 22.
[0037] FIG. 27 is a perspective view of the coolant bushing of FIG.
26.
[0038] FIG. 28 is a cross-sectional, perspective view of the
coolant bushing of FIG. 26.
[0039] FIG. 29 is a perspective view of an alternative embodiment
of the coolant bushing of FIG. 27.
[0040] FIG. 30 is a cross-sectional, perspective view of an
alternative embodiment of the coolant bushing of FIG. 28.
[0041] FIG. 31 is a perspective view of a further alternative
embodiment of the coolant bushing of FIG. 27.
[0042] FIG. 32 is a cross-sectional, perspective view of a further
alternative embodiment of the coolant bushing of FIG. 28.
[0043] FIG. 33 is a perspective view of an alternative embodiment
of valve and actuator of FIG. 20.
[0044] FIG. 34 is a cross-sectional view of the valve and actuator
of FIG. 33.
[0045] FIG. 35 is a perspective view of a further alternative
embodiment of valve and actuator of FIG. 20.
[0046] FIG. 36 is a cross-sectional view of the valve and actuator
of FIG. 35.
DETAILED DESCRIPTION
[0047] There are several design variants of rotary
electro-hydraulic actuators as known in the prior art and shown in
FIGS. 1-3. FIG. 1, for example illustrates a single vane rotary
actuator. Such an actuator 100 includes a base or lower cover 102.
A housing 104 with a cylindrical interior extends from the lower
cover. An upper cover (not shown) covers the other end of the
housing 104. The actuator 100 further includes a rotational
assembly 106, which includes a hub 108 and a vane 110. In addition,
the actuator includes a partition wall 120. The vane in conjunction
with the partition wall divides the interior of the housing into
two chambers 112, 114. The actuator also includes an input port 116
and a return port 118. Accordingly, when hydraulic fluid is pumped
into the actuator through the input port 116 and fluid is allowed
to exit through the return port, the actuator will rotate in a
first direction. When fluid is pumped into the actuator through the
return port 118 and fluid is allowed to exit through the input
port, the actuator will rotate in the opposite direction. A shaft
122 extends from the hub 108 to transfer torque to the device to be
actuated. The flow direction and rate are controlled via a remote
or onboard control valve. These are usually spool valves or poppet
valves.
[0048] FIGS. 2-3 illustrates an alternative electro-hydraulic
actuator as known in the prior art using a cylinders 202, 204 and
pistons 206, 208 connected by a rod 210. The rod 210 includes teeth
214 that engage with teeth 216 on a rotating member 218. In such a
system, the hydraulic pressure is applied to one or the other
piston through ports 220 or 222. This causes the rod 210 to
translate, which imparts rotational motion to the rotary member
218. This rotary motion can be output from the actuator via a hub
224.
[0049] In almost all rotary applications the valve is of the single
vane design, such as shown in FIG. 1. However, in such actuators,
the torque that the actuator is capable of producing is
proportional to the effective surface area of the vane. In order to
increase the available torque, the vane surface area, and thus the
size of the actuator must be increased. Accordingly, it may be
advantageous to utilize an actuator having more than one vane. For
example, using two vanes effectively doubles the available torque
without increasing the overall size of the actuator. Provided,
however, that increasing the number of vanes allows for increased
torque by increasing the vane areas but with a reduction of the
range of rotational movement of the actuator. A single vane
actuator has a potential rotational capability of about 300
degrees, depending of the chamber partition wall and vane
thickness, while a two-vane actuator rotation have about 150
degrees and a three vane actuators has about 80 degrees rotation,
etc.
[0050] One of the major challenges of a multi-vane rotary actuator
is to route the pressurized hydraulic fluid to the input and output
ports of the actuator. For example, when the valve is commanded to
move clockwise, one (or more) chamber(s) is pressurized while
another one (or more) chamber(s) is discharged to a reservoir. The
routing of the fluids may be controlled via a multiport spool valve
but the required input and output passages required to be routed
from the spool valve to the chambers can be complex and requiring a
multi-way spool valve options that are expensive and significantly
increase the overall size of the actuator. Embodiments of the
present invention address this and other deficiencies of the prior
devices.
[0051] FIGS. 4-5 illustrate a valve assembly 301 and actuator 308
in accordance with embodiments of the present invention. A
butterfly valve plate 302 is positioned within a valve housing 304.
The valve housing may be installed in the exhaust system of an
internal combustion engine. The butterfly valve plate 302 may be
opened and closed to control the flow of fluid through the housing
304. Support posts 306 extend from an outside surface of the
housing. The support posts may be used to mount an actuator 308.
The posts may also provide thermal insulation for the actuator
assembly, protecting it from the heat of the exhaust gases passing
through the housing 304.
[0052] In addition, insulating washers 310 may be mounted on posts
306 to minimize the conductive heat transfer. Other means of
minimizing convective and radiant heat transfer into the actuator
is making the use of heat shields. These heat shields can be in for
of single-walled or multi-walled designs containing insulating
materials or just relay on an air gap. Alternatively, other
mounting means may be used to secure the actuator 308 to the valve
housing 304. Additionally, the lower cover 314, housing 318 and
upper cover 312 may include holes 322 (see FIG. 7) that provide a
means for securing the actuator 308 to the posts 306 and the valve
assembly 304. For example, bolts 323 (shown in FIG. 4) may be
inserted through holes 322 into posts 306. In the illustrated
embodiment, the actuator assembly is attached to the flow
modulating device, valve 301, via four M10 bolts 323. Depending on
the geometric shape and size of the actuator the number of bolts
can be reduced in number or changed in size.
[0053] FIG. 6 illustrates an embodiment of the valve assembly 301.
The valve in this embodiment is a butterfly valve. The main
function of the butterfly valve described in this embodiment is to
modulate fluids in internal combustion engines. Although references
are made that the butterfly is being used on internal combustion
engines it can be used to control fluid flow for many applications,
ranging from engines, industrial and residential fluid control
systems. These fluids can be cold or extremely hot. In certain
applications gaseous exhaust temperatures reach temperatures in
excess of 800.degree. C. and careful selection of the alloys is
required. Modulating sealing surfaces, shaft journals and bearings
and shaft seals are the major wear components of the valve and high
nickel and cobalt alloys are required. In the case of this
embodiment, a butterfly valve is being described because of its
pressure balancing characteristics but flap valves can also be
considered for this actuator application.
[0054] The illustrative valve assembly 301 includes a main valve
housing 304. A shaft 332 extends through a sidewall into the
interior of the housing 304. The valve assembly further includes a
butterfly plate 406 positioned inside the housing 304. The
butterfly plate 406 includes first and second vanes 330 extending
in opposite directions. The butterfly plate is connected to a shaft
332 that extends through the sidewalls on opposite sides of the
housing. The shaft 332 may extend beyond the house wall on the side
adjacent the actuator 308 in order to engage with a hub of the
actuator. The butterfly valve vanes 330 may be connected with the
shaft 332 by fasteners 334, such as retention screws. The valve
assembly may also include bushings or bearings 408 and a shaft end
cap 412. The end cap may be secured to the housing 304 by screws
413 or other fasteners in order to secure the shaft 332 in
position. The valve can be configured to attain a normally open or
a normally closed butterfly valve condition by adjusting the vane
assembly or switching the hydraulic input/output ports.
[0055] The actuator of the present invention is not limited to use
with the butterfly described herein. In addition to a butterfly or
flap valve, embodiments of the actuator may be used with any
flow-modulating device, including for example single or multiport
gate valves, globe valves, disk valves, stem valves, or other
appropriate valves. In addition, the actuator may be used in
rotational and linear mechanical motion devices. The actuator may
be used in any device that can accept rotational motion as an
input, including devices where rotational motion is transformed
into linear or other motion by screws, linkages, gear trains,
rack-and-pinion assemblies, etc.
[0056] Embodiments of the actuator 308 are illustrated in FIGS.
7-8. The main function of the actuator is to position the fluid
modulating valve 301 according to the required engine control
parameters. The actuator represented in this embodiment is a dual
vane design and has a total rotational travel of 85 degrees. Other
vane configurations or rotational travel would be apparent to one
of skill in the art.
[0057] The actuator 308 may comprise a housing 318. The housing is
sealed by an upper cover 312 and a lower cover 314. However, while
this and other embodiments described herein illustrate an actuator
assembly having a housing with separate upper and lower covers, it
should be understood that two or more of these components may be
formed as a single piece. For example, the housing and upper cover
may be formed as single piece, or the housing and lower cover may
be formed as a single piece.
[0058] Embodiments of the actuator may also include a vane 504 for
rotation within the housing 318. The vane 504 may rotate on a
bearing 508 and main include vane tip seals 522. The housing 318
and covers 312, 314 may also incorporate housing seals 510 to
better seal between the components. In addition, a main shaft seal
assembly 514 may be used to seal against the shaft 322 extending
from the valve assembly 301. The shaft 322 may also engage with a
standalone shaft sensor or contain part of the shaft positioning
sensor assembly when used in conjunction with a shaft position
sensor 518 and/or an electronic control circuit board 519
positioned beneath a cover 517.
[0059] Single or multiple actuator control valves may be used in
the application. The valve may be a two-way/two-position cartridge
spool valve with a proportional design or any other appropriate
valve. The valve may be incorporated into the upper cover 312 or
into the lower cover 314 and fluid may be routed to chambers of the
actuator as required. Alternatively, the valve may be incorporated
into the side of the actuator. The control valve 516 may be coupled
to fittings 327, 328 for connecting with a hydraulic pump of the
hydraulic system or a pneumatic pump if a pneumatic system is
used.
[0060] As shown in FIGS. 7-8, the upper cover 312, housing 318 and
lower cover 314 may include through holes 320. Bolts, screws or
other fasteners 321 may be inserted into these holes 320 in order
to secure the covers 312, 314 to the housing 318. In the
illustrated embodiment, these fasteners include eleven M6 bolts.
Depending on the geometric shape and size of the actuator the
number of bolts can be reduced in number or changed in size. The
holes 320 may be internally threaded or may provide other features
that contribute to securing the components. The actuator 308 may
have a generally central axis 324 about which the rotational
assembly of the actuator rotates. The upper cover 312 may have
reinforcing struts 326.
[0061] As shown, by example, in FIG. 7, a bottom cover 314 of an
actuator 308 may include an opening 336. A hub 338 of the
rotational assembly of the actuator may be exposed through the
hole. As shown in FIG. 9, the hub 338 may include a female socket
340 recessed into the hub. The socket 340 may include splines 342
that engage with splines 333 formed on shaft 332. The splines can
be arranged symmetrically around the whole circumference or can be
asymmetric or lost tooth format. The hub can be designed of any
alloy, but given the tendency of high torque requirement and high
temperature applications, the alloy selected will be of low heat
conducting, high toughness and low wear characteristics.
[0062] FIG. 9 depicts an embodiment of the actuator main housing
318 and vane rotational assembly 648. The depicted main housing
consists of an extruded aluminum profile that attains near net
shape conditions. Although other manufacturing processes such as
die casting, forging, etc. can be used for this part, extruded
aluminum profile provide near net shape parts that do not require
major post manufacturing processes, offer dimensional stability and
high physical properties. Extruded aluminum alloys also can be
easily coated or plated with wear reducing and low friction
coatings and plating.
[0063] The internal profile is designed to contain the travel end
stops 612 and sealing surfaces 614 of the rotating vane 504. Corner
radii 604 of the internal profile are shaped to allow for any
secondary profile clean up using robust machining tools. Passages
for assembly bolts 606, attachment screws 607 and coolant routing
608 are extruded to minimize the post machining processes.
[0064] The extrusion design option also allows the sizing of the
actuator. The torque capabilities of the actuator are directly
proportional to the area exposed to the pressurized working fluid.
The area is a function of the diameter and length of the vane 504,
and thus extrusion generates an easy option to cut the actuator
length within the extrusion length. The length of the actuator 610
is partially restricted by the packaging constraints but in general
range from 25 mm to 75 mm. The actuator vane depicted in this
application is 35 mm length to achieve the specified torque
characteristics of 40 Nm of torque.
[0065] The main housing depicted in FIG. 9 can be configured to
house the working fluid inlet and outlet ports 327, 328 and the
electric hydraulic control valves. Although inlet and outlet ports
depicted are of the external flare style and of different size to
eliminate assembly mistake they can be of any size, type and gender
to achieve the required connection point and mistake proofing.
[0066] The actuator main housing is for a dual vane actuator design
but the extrusion profile could be designed into any shape to
achieve from single to multi vane actuator design with the gain in
torque output but with loss of rotational range. As shown in FIG.
9, the housing has a generally cylindrical inner cavity. Partition
walls 644 extend from an inner surface 646 of the cavity. A
rotational assembly 648 is positioned for rotation about a central
axis of the actuator housing. The rotational assembly includes a
hub 338 with a first vane 654 and a second vane 656 extending from
the hub.
[0067] To minimize internal leakage, the tip of the vanes 654 and
656 can be sealed against the inner surface 646 of the housing 318
by tip seals 614 or by using tightly toleranced parts and thermal
conductive matched. Chamber seals 662 seal the ends of partition
walls 644 against hub 338. In addition, housing seals are fitted
into grooves 664 in order to seal upper and lower covers to the
housing 318. In addition, bearings (not shown) may be utilized to
facilitate rotation of the rotational assembly 318. The bearings
may be deep groove bearings.
[0068] FIG. 10 depicts a vane rotational assembly configuration
used in an embodiment of the invention. Main functions of the vane
in this application are to house the bearings, serve as the working
fluid manifold, transmit rotational motion to device to be driven
shaft and seal the working chambers. This seals can be of various
types: force activated wiper seals and labyrinth style seals.
[0069] The area of the actuator vane exposed to the pressurized
working fluid determines the performance to of the actuator
assembly. In multi-vane actuator applications one of the main
challenges is the routing of the working fluid to and from the
required chambers and its manufacturability. Embodiments of the
vane actuator may be manufactured by various methods, including
extrusion and investment casting. Vane communication passages or
manifolds 702, 703 are depicted in FIG. 10. These passages can be
achieved via investment casting, 4-axis electrical discharge
machining (EDM) or cross drilling. Spark eroding the communication
channels with a 4 axis EDM process is slow and expensive and
challenged by the line of sight and passage size restricted by the
vane interior diameter feature that connects to the output shaft of
the shaft from the device to be driven. Investment casting allows
the option to cast the passages in circumferential geometry and
allows for non-circular cross-section allowing the flow to be
maximized. Special cores and core support have been designed to
achieve this configuration.
[0070] The size and the geometry of this passage control the
performance of the valve. Smaller holes or inserted orifii may
restrict the fill of the secondary chambers while inserted check
valves can time the fill of the secondary chambers. The flow area
of the communication passages can be 10 to 50 mm.sup.2 but in
general are sized to 30 mm.sup.2 as depicted in this embodiment to
adapt commercially available check valves.
[0071] In the case of investment casting and extrusion, which are
of the near net shape manufacturing processes, features 704 are
formed into the vane geometry to minimize the final machining
process and help in the use of highly robust cutting tools to
minimize the manufacturing process cycle. Undercut areas 706 in the
vane to hub area may be used to eliminate the need to use very
small diameter contouring tools as well as serve as the starting
edge for the cross drilling, 4-axis EDM or press feature for the
check valves or orifii.
[0072] Sealing of the working chambers may be achieved with vane
tip seals inserted into channels 710 formed at the tip of vanes
712, 713 and hub radial seals 708. These seals can be dynamic seals
like labyrinth seals or force activated static seals. Force
activation is mainly achieved via elastomers or metal springs while
the wiping element is a low friction chemically inert compound such
as Teflon.
[0073] FIG. 10 depicts an internally supported vane via the
bearings toward the hub extensions in the covers, externally
supported vane is also possible but such a design does not allow
for minimized packaging.
[0074] As illustrated in FIG. 10, an actuator in accordance with
embodiments of the present invention flows the working fluid
through strategically sized flow channels 712, 713 within the
structure of the vane assembly. The ports and passageways are sized
to provide dampening and improve the stability of the valve and can
also be provided with pressure check valves or reed valves to
dampen the rotation of the valve and reduce any instability due to
pulsations driven back via the output shaft.
[0075] For example, vane 713 may include a port 723 formed in a
first face 733 of the vane. The port 723 is connected via an
internal passageway or manifold 703 to a port adjacent the opposite
face 752 of the second vane 712. Likewise, a port 722 on the first
face 732 of the vane 712 is connected via an internal passageway or
manifold 702 to a port 743 on the opposite face 753 of vane
713.
[0076] In this manner, a pressurized flow of hydraulic fluid is
applied to face 733 of vane 713 inducing the assembly to rotate in
a clockwise direction. The fluid then passed through the body of
the actuator assembly, through passageway 703. The hydraulic fluid
then applies pressure, to the opposite face 752 of vane 712
increasing the clockwise torque on the assembly. In a like manner,
return flow applies a force to the face 753 of vane 713 to rotate
the assembly in a counterclockwise direction. The return flow of
fluid passed through passageway 702. The hydraulic fluid then
applies pressure to the face 732 of vane 712 increasing the
counterclockwise torque on the assembly. Flow from the primary
chamber to the secondary chambers can be delayed or dampened by the
use of orifices and/or check valves. The use of such devices can
increase the accuracy of the actuator and dampening characteristics
due to the torque fluctuations imparted on the output shaft.
[0077] As illustrated in FIGS. 9-10, embodiments of the invention
may use a two-vane rotational assembly. The assembly includes a hub
762. Vanes 712 and 713 extend from the hub. In this embodiment, the
vanes are offset at an angle less than 180 degrees in order to
accommodate flow channels and valves in the actuator housing. The
angle between the vanes will affect the maximum rotation of the
actuator and may be any appropriate angle up to 180 degrees.
Alternatively, the vane rotational assembly may have more or fewer
vanes. The rotational assembly may be formed from multiple
components joined together by known means. Alternatively, some or
all of the components may be formed from as a single piece.
[0078] The support of the rotating members of this valve can be
external or internal to the shaft/vane assembly. The use of shaft
support in the form of ball bearings, needle bearings, bushings
exclusively or combination thereof can generate packaging and cost
advantages.
[0079] As illustrated in FIGS. 10-11, embodiments of the vane
assembly include a hub 762. Vanes 712 and 713 extend from the hub.
A socket 740 is recessed into hub 762 for engaging a shaft
extending from the device to be actuated. The socket 740 may
include splines 742 for engaging corresponding splines on the
device shaft. A bearing surface 749 may be formed on a surface of
the hub 748 in order to engage with a bearing 750 for rotational
movement.
[0080] FIG. 12 is a cross-sectional view of an actuator assembly of
an embodiment. The actuator assembly includes an upper actuator
cover 802 and lower actuator cover 804. A function of the covers is
to seal the working chambers 806 of the main housing, guide the
vane rotation via the cover extension shafts 808, 809 and route the
coolant as depicted in FIGS. 13-15. As illustrated in FIGS. 13-15,
the upper cover 802 may include closed channels 812 drilled, casted
(lost foam invested casting, etc.), formed or cut into the cover.
This cooling channels can be machined or cast into the upper cover
alone, lower cover alone or into both. The requirement is dictated
by the source of the heat: conductive, convective or radiant.
Hydraulic fluid provided by a hydraulic pump may be passed through
these channels. For example, bypass fluid not used to actuate the
actuator may be passed from the pump through the channels before
being returned to a reservoir. This fluid may be used to cool the
bottom cover and thus provide thermal insulation for the actuator
308. Although the cooling circuit described in this invention makes
use of the existing working fluid, either in parallel or in series
circuits, the cooling circuit can also be an independent cooling
system where engine coolant or any other cooling fluid can be
used.
[0081] The origin of the oil can either be from diverting the
supply line or passage, and flow may be determined by the amount of
oil flow to achieve the cooling action. Sizing of the flow channel,
by the use of casting techniques, inserted orifices, etc.,
determines the flow according the pressure available. Flow can also
"timed" via a check valves that cut the diverted cooling oil flow
at low oil pressure conditions. Oil pressure is directly related to
engine load and thus to the temperatures in the exhaust, i.e. at
idle where oil pressure is low (e.g. 20 psi) cooling flow is not
required because exhaust gas temperatures are fairly low and do not
affect the performance and durability of the actuator.
[0082] The cover 802 may have an inlet port 814 formed in an inside
surface 818 of the cover that receives hydraulic fluid flowing
though the valve and housing of the actuator. The fluid then passes
through channels 812 formed in the cover. The fluid then exits
through a port 816. Inlet port 814 and outlet port 816 may be
located at the cross over ports in the actuator housing. The
cooling channels may create a cooling curtain that is sized to
achieve the maximum surface area. The upper cover 802 may have an
opening 838 through which the hub or shaft of the rotational
assembly may be exposed.
[0083] Cooling flow may be made through the upper cover.
Alternatively, the cooling flow can also pass through the main body
or lower cover. Or the flow may pass through multiple or all of
these portions depending which part of the actuator may benefit
from being be cooled or protected. These flow passages can be in
the form of drilled, caste or formed passages or rerouted by
external conduits such as hoses and tubes.
[0084] As shown in FIG. 12, the upper cover in addition to above
mentioned functions may also contain electronic control circuitry,
electric/electronic input/output circuitry 901 and/or a shaft
position sensor 905. The shaft position sensor may be a standalone
sensor. An additional function of the lower cover is to house a
main shaft seal 907, house additional sealing components 909 that
contain minute exhaust leaks during extreme engine transients and
serve as a structural interface to the valve or other device to be
driven, for example through support posts 911. Although the figure
depicts covers without any control valves, the castings can easily
be designed to contain the fluid control valve.
[0085] As depicted in FIG. 16, lower cover, and FIG. 17, upper
cover, embodiments of the invention include a configuration in
which routing and control of the coolant circuitry is positioned
within a single-piece aluminum component. This unique design allows
for one casting that fits multiple applications and that provides
both lower and upper covers. The lower and upper raw castings or
forgings are designed to be common and then machined according to
the application. Machining variation can generate many different
variants of the actuator according to its application, including: a
smart drive by wire actuator, a passive actuator. For example, the
lower cover 804 shown in FIG. 16 use the same casting as the upper
cover 804 of FIG. 17. The cover 802 may then be processed or
machined to create an opening 836 to accommodate a shaft seal and
become the lower cover. The cover may be processed to have an
opening 838 that may accommodate sensors or other control circuitry
and thus become an upper cover. In this way, the actuator may be
internally cooled, top cooled or bottom cooled. It may also use
fluid or gaseous cooling, serial or parallel cooling or no cooling.
Such a symmetric configuration also has advantages for
manufacturing tooling cost, only one casting or forging tool is
required. The coolant circuit can be present in the upper or lower
cover or both depending of the application. Aluminum lost foam,
investment casting, forging and brazed, billet machined and brazed
processes may be the processes of choice for this design but is
dependent on production volume.
[0086] As shown in FIGS. 18-19, in embodiments of the present
invention, directional and modulating control of the working fluid
from one chamber to another of the actuator may be controlled via
an electronic proportional solenoid 916. Although hydraulic and
pneumatic fluids are discussed in this application, any
compressible or non-compressible gases and liquids can be used as
the working fluid. The proportional solenoid can be of the push,
pull or dual actuated style. The modulation can be achieved via a
single multiport spool valve, multiple dual port spool valve or
pairs of proportional poppet valves. Embodiments of the invention
may include a control system that uses the valve, whether
proportional, poppet or other, to maintain the position of the
actuator. For example, the control system may include one
differential or two absolute pressure sensors to sense the
differential pressure across the two chambers. The control system
periodically compares the pressure. If the control system detects a
pressure differential, the system compensates by appropriately
increasing or decreasing the fluid in the chambers. This balancing
of fluid pressure between the chambers is accomplished using one or
more of the valves as described. In this manner, the actuator can
maintain the position of the actuator and thus the valve or other
device being driven by the actuator.
[0087] Sizing of the ports and number of valves determines the
response time of the actuator and the pressures losses that
directly results in the loss of torque. The valve size may vary as
appropriate for the application as would be understood by one of
ordinary skill in the art. The actuator can be configured with the
proportional solenoid valve in the upper cover, main actuator
housing or lower cover. The solenoid depicted in FIG. 18 is
designed to be installed in the actuator main housing due to
packaging constraints and to reduce the overall size of the
actuator mechanism.
[0088] The proportional valve(s) can contain mechanical position
feedback or electronic position feedback. In the case of mechanical
feedback the spool of the valve is biased via a spring cam
mechanism to attain and maintain the commended position. If
electronic position feedback is used, Hall effect or similar
sensors are being used to obtain spool position feedback. In an
alternative embodiment, pressure feedback from the actuator working
chambers may be used in commanded positioning and to aid in the
critical dampening of the actuator/valve. These types of feedback
maybe used to attain and maintain the spool position, which
controls the actuator shaft position.
[0089] In embodiments of the invention, the position of the
actuator is driven by the actuation of a proportional cartridge
valve through an analog, pulse width modulated (PWM) or digital
signals generated by an Engine Control Unit (ECU). The system can
further be augmented with electronic/hydraulic logic to increase
the self-sufficiency of the valve such as position, response time,
etc.
[0090] In accordance with embodiment of the invention, it may be
desirable to provide information regarding the rotational position
of the rotating assembly such as the rotational position of the
output shaft 332 shown in FIG. 6 or the female socket 340 shown in
FIG. 9. Such position feedback can be open loop or closed loop
type. Open loop feedback depends only on the command control of the
cartridge valve. Closed loop depends on one or more sensors that
are either internal or external to the actuator. These sensors may
be contact or contactless sensors, including linear variable
differential transformer (LVDT), rotary variable differential
transformer (RVDT), Hall effect, resolvers, analog wipers, etc.
[0091] Embodiments of the actuator may be configured with or
without a shaft position sensor. In the case of open loop control
the shaft position sensor is not required and the engine uses other
sensors as well as mechanical hydraulic control valve force
feedback to control the actuator and thus modulate the valve. In
the case of closed loop control the shaft position sensor may be
used for initial start-up calibration or continuous control. As
shown in FIGS. 17 and 19, the upper cover 802 may include a cavity
or recess 838 in which a sensor may be positioned. The cavity 838
may be covered or sealed by a cover 840. The cover 840 may be
secured to the upper cover 802 by screws 844 or other fasteners.
Alternatively, the cover may itself have threads or engagement
surfaces that engage with corresponding portions of the upper cover
802.
[0092] Embodiments of the shaft position sensor can be of the
standalone design were position feedback is being monitored by a
remote centralized control system or installed on a circuit board
for actuator onboard circuit design option for decentralized
actuator/valve control system or hybrids thereof. In the case of
standalone shaft position systems the shaft position sensor can be
of the variable transformer, hall effect, magneto-resistive,
inductive, capacitive, resistive, optic type or variants of
thereof. In the case of integrated shaft positions sensor, the
sensor is integrated into the circuit board of the decentralized
control system and can be of the many variants discussed above.
[0093] FIG. 4 depicts an embodiment of the invention that includes
a butterfly fluid modulating valve 302 with a multi-vane actuator,
single-multiport proportional spool valve and shaft position
feedback. This assembly may be monitored and controlled via remote
controllers that can be standalone actuator controllers but can
also be part of the engine control unit. This design has the
disadvantage that electronic control, power and communication
require large number of wires and complex electric connectors.
Depending on the feedback and communication 12 wires or more are
required. Such configuration suffers from communication time lags,
susceptible to electromagnetic interference and electric
wire/connector failure due to the harsh environmental conditions
existent in the engine compartment.
[0094] In another embodiment, the valve is designed to contain its
own controller. The communication can be analog or digital. Analog
communication can be of the voltage or current type and in the
digital case it can be PWM (Pulse Width Modulated), or via CAN
(Central Area Network) and its variant. For industrial application
these communication can be configured to use Ethernet, RS232, RS
485 and its other variants. This design option retains full
actuator onboard control and onboard diagnostics. The circuit board
components are selected for harsh environmental conditions and
fully encapsulated to protect for cooling fluid exposure with the
objective to protect the circuit from external and cool the circuit
internal heat being generated. The fully encapsulated circuit board
layout is configured to integrate all required major building
blocks required for the control, protection and diagnostics of the
actuator and the connection points via compliant pins to the input
and output connections points for external or internal
communications or control such as proportional solenoid valves. The
encapsulated circuit board would transfer its heat via thermally
conductive encapsulant or encapsulated heat sinks that are directly
in contact with the cooling circuit.
[0095] The single layer or multilayer circuit board of such an
embodiment of the actuator would contain all or part of the
following main building blocks: microcontroller, a spool or poppet
valve driver, circuit protection, shaft position sensor and I/O
connection points in the form of hard mounted connector or flying
lead. These building blocks can be generated using discrete
components or highly integrated using proprietary AISIC/FPGA
technology. The package size of the circuit board fits into
machinable areas of 20 mm in diameter to 60 mm in diameter. As
shown in FIGS. 17 and 18 it may be installed to the upper cover 802
via screws 844, clips or other retention mechanism commonly used in
the industry. Alternatively, the circuitry could be installed in
the main housing 308 (see FIG. 4).
[0096] The actuator described herein may be referred to as a remote
actuator. However, it will be understood that actuator can be
remote but that, alternatively, its function and performance can
also be built into the actuator or a valve associated with the
actuator to reduce packaging and cost.
[0097] An embodiment of the present invention is shown in FIGS.
20-28. In the illustrated embodiments, a valve assembly 902 is
attached to and functionally connected with an actuator assembly
904. Bolts 906 pass through holes 938 in the valve assembly 902 and
engaged threaded holes in the actuator assembly 904. Other
attachment mechanisms may be used. The actuator assembly may be an
electro-hydraulic actuator as describe herein with respect to FIGS.
1-19. Alternatively, the actuator assembly may be an
electro-mechanical actuator as illustrated in FIGS. 20-28. The
actuator assembly may be any actuator that would benefit from
cooling or thermal isolation as described herein.
[0098] The valve assembly 902 includes a valve body 908. The valve
body has a central, generally cylindrical through bore 910. A
butterfly valve plate 912 is positioned within the bore 910. A
shaft 914 passes through a central passage 916 formed within the
butterfly plate 912. The valve assembly also includes a
perpendicular opening 920 formed through a sidewall of the central
bore 910 adjacent to the actuator assembly 904 and a second
perpendicular opening 918 formed through a sidewall of the central
bore 910 opposite the actuator assembly 904. The shaft 914 passes
at least partially through these openings 918, 920 to allow the
butterfly plate 912 to rotate within the valve housing bore 910.
Bushings 922 may be placed around the shaft 914 within the openings
918, 920 to allow smooth rotation of the shaft.
[0099] A position or other sensor 924 may be positioned over the
opening 918 to engage the shaft 914. Adjacent the actuator assembly
904, the shaft 914 may extend through the hole 920 and into the
actuator assembly to mechanically engage with the actuator. A
flange 926 may extend from a sidewall of the shaft 912, and various
bushings 928 and seals 930 may be positioned around the shaft.
[0100] The valve assembly 902 may include a coolant ring 934
positioned between the valve housing 908 and the actuator assembly
904. As particularly illustrated in FIGS. 23-25, embodiments of the
coolant ring may be positioned within a cavity 936 formed in the
actuator side of the valve housing 908. A flange 940 of the valve
housing 908 may extend around all or part of the coolant ring 934
such that the valve housing comes in contact with the actuator
assembly 904 around the periphery of the coolant ring. The coolant
ring may include a central bore 946 through which the shaft 914 can
pass.
[0101] The geometry and routing of the coolant channels can be of
any configuration depending on the cooling objective. In the case
of heat transfer barrier helical configuration is adopted were the
coolant is routed from the OD towards the ID as depicted in FIGS.
31-32. In the case of shaft cooling the cooling function is
concentrated around the shaft as depicted in FIGS. 27-28. In the
case heat barrier and shaft cooling is required a cooling ring with
both cooling channels may be adopted.
[0102] As illustrated in FIGS. 26-30, the coolant ring 934 may
include interior radial crossover coolant channels 942 that route
the coolant from the inlet port 948 to the circumferential flow
channel 964 adjacent to the shaft back to the outlet port 949. A
port sealing element 958 (FIG. 21) may be used to connect the
coolant channels 942 in the coolant ring with fluid passages 960 in
the actuator assembly. The port sealing element 958 may be a tube
or any other sealing feature such as gaskets, face or radial
O-rings. The I/O ports depicted here are on the same side 180
degrees apart but these ports can be in any orientation and on
alternate sides depending how the coolant is routed. The coolant
fluid can be any appropriate fluid, including hydraulic fluid used
to actuate an actuator assembly, bypass hydraulic fluid not used to
actuate the actuator assembly, engine coolant fluid or any other
fluid as would be apparent to one of ordinary skill in the art.
[0103] The coolant channels 942 may be offset from the centerline
of the ring toward the valve housing 908. The side of the coolant
ring adjacent to the actuator assembly also may have one or more
recesses 944 formed in the surface. The offset of the coolant
channel 942 combined with the recess 944 may provide a number of
advantages, including increasing the thermal isolation provided by
the coolant ring to the actuator assembly as well as reducing the
amount of material necessary to manufacture the coolant ring.
[0104] To enhance the heat transfer from the valve body to the
coolant via the coolant ring, selection of alloys is optimized and
contact resistance is minimized by the use of wave springs and/or
thermally conductive paste or epoxies. For example, a wave spring
932 may be placed between the actuator body 904 and the cooling
ring 934 to press the cooling ring against the valve assembly 902.
Additionally, a thermally conductive material 933, including a
paste or epoxy, may be positioned between the surface of the
cooling ring 934 and the valve assembly 902 or between the cooling
ring 934 and the actuator body 904.
[0105] The coolant ring 934 may be provided as a modular ring or
system of rings. In this manner, a system designer may choose a
size and cooling capacity of the cooling ring based on the
application, taking into account various factors, including:
temperatures to which the valve assembly will be subjected,
temperature limits of the actuator assembly, duty cycle of the
system, ambient temperature, cooling capacity of the cooling fluid,
and other factors as would be understood by one of ordinary skill
in the art.
[0106] In embodiments as illustrated in FIGS. 23-25, the shaft 914
passes through a central passageway 916 of the butterfly plate 912.
The illustrated shaft has a generally cylindrical profile. However,
a portion of the shaft within the plate passage way is milled or
otherwise formed to create a flat section 950. The butterfly plate
includes a through hole 952. This through hole is offset from the
centerline of the butterfly plate so that it lies generally
adjacent to but extending slightly into a side edge 954 of the
central passageway 916. A pin 956 is inserted into the hole 952.
The pin engages the flat section 950 of the shaft 914 and prevents
the shaft from rotating within the central passageway 916 of the
butterfly plate. A reinforcing structure 962 may be formed on the
butterfly plate adjacent the through hole 952 to provide a stronger
supporting structure for the pin 956.
[0107] In this manner the butterfly plate and shaft may be
effectively locked together for coordinated movement without the
need to drill through the diverse materials of the plate and shaft
or without the need to exactly align complimentary holes or other
features formed in the plate and shaft.
* * * * *